net/9p/mod.c

   1 /*
   2  *  net/9p/9p.c
   3  *
   4  *  9P entry point
   5  *
   6  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2
  12  *  as published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to:
  21  *  Free Software Foundation
  22  *  51 Franklin Street, Fifth Floor
  23  *  Boston, MA  02111-1301  USA
  24  *
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/moduleparam.h>
  29 #include <net/9p/9p.h>
  30 #include <linux/fs.h>
  31 #include <linux/parser.h>
  32 #include <net/9p/client.h>
  33 #include <net/9p/transport.h>
  34 #include <linux/list.h>
  35 #include <linux/spinlock.h>
  36
  37 unsigned int p9_debug_level = 0;        /* feature-rific global debug level  */
  38 EXPORT_SYMBOL(p9_debug_level);
  39 module_param_named(debug, p9_debug_level, uint, 0);
  40 MODULE_PARM_DESC(debug, "9P debugging level");
  41
  42 /*
  43  * Dynamic Transport Registration Routines
  44  *
  45  */
  46
  47 static DEFINE_SPINLOCK(v9fs_trans_lock);
  48 static LIST_HEAD(v9fs_trans_list);
  49
  50 /**
  51  * v9fs_register_trans - register a new transport with 9p
  52  * @m: structure describing the transport module and entry points
  53  *
  54  */
  55 void v9fs_register_trans(struct p9_trans_module *m)
  56 {
  57         spin_lock(&v9fs_trans_lock);
  58         list_add_tail(&m->list, &v9fs_trans_list);
  59         spin_unlock(&v9fs_trans_lock);
  60 }
  61 EXPORT_SYMBOL(v9fs_register_trans);
  62
  63 /**
  64  * v9fs_unregister_trans - unregister a 9p transport
  65  * @m: the transport to remove
  66  *
  67  */
  68 void v9fs_unregister_trans(struct p9_trans_module *m)
  69 {
  70         spin_lock(&v9fs_trans_lock);
  71         list_del_init(&m->list);
  72         spin_unlock(&v9fs_trans_lock);
  73 }
  74 EXPORT_SYMBOL(v9fs_unregister_trans);
  75
  76 /**
  77  * v9fs_get_trans_by_name - get transport with the matching name
  78  * @name: string identifying transport
  79  *
  80  */
  81 struct p9_trans_module *v9fs_get_trans_by_name(char *s)
  82 {
  83         struct p9_trans_module *t, *found = NULL;
  84
  85         spin_lock(&v9fs_trans_lock);
  86
  87         list_for_each_entry(t, &v9fs_trans_list, list)
  88                 if (strcmp(t->name, s) == 0 &&
  89                     try_module_get(t->owner)) {
  90                         found = t;
  91                         break;
  92                 }
  93
  94         spin_unlock(&v9fs_trans_lock);
  95         return found;
  96 }
  97 EXPORT_SYMBOL(v9fs_get_trans_by_name);
  98
  99 /**
 100  * v9fs_get_default_trans - get the default transport
 101  *
 102  */
 103
 104 struct p9_trans_module *v9fs_get_default_trans(void)
 105 {
 106         struct p9_trans_module *t, *found = NULL;
 107
 108         spin_lock(&v9fs_trans_lock);
 109
 110         list_for_each_entry(t, &v9fs_trans_list, list)
 111                 if (t->def && try_module_get(t->owner)) {
 112                         found = t;
 113                         break;
 114                 }
 115
 116         if (!found)
 117                 list_for_each_entry(t, &v9fs_trans_list, list)
 118                         if (try_module_get(t->owner)) {
 119                                 found = t;
 120                                 break;
 121                         }
 122
 123         spin_unlock(&v9fs_trans_lock);
 124         return found;
 125 }
 126 EXPORT_SYMBOL(v9fs_get_default_trans);
 127
 128 /**
 129  * v9fs_put_trans - put trans
 130  * @m: transport to put
 131  *
 132  */
 133 void v9fs_put_trans(struct p9_trans_module *m)
 134 {
 135         if (m)
 136                 module_put(m->owner);
 137 }
 138
 139 /**
 140  * init_p9 - Initialize module
 141  *
 142  */
 143 static int __init init_p9(void)
 144 {
 145         int ret = 0;
 146
 147         p9_error_init();
 148         printk(KERN_INFO "Installing 9P2000 support\n");
 149         p9_trans_fd_init();
 150
 151         return ret;
 152 }
 153
 154 /**
 155  * exit_p9 - shutdown module
 156  *
 157  */
 158
 159 static void __exit exit_p9(void)
 160 {
 161         printk(KERN_INFO "Unloading 9P2000 support\n");
 162
 163         p9_trans_fd_exit();
 164 }
 165
 166 module_init(init_p9)
 167 module_exit(exit_p9)
 168
 169 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 170 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 171 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 172 MODULE_LICENSE("GPL");